GK SDK 源码库: XMIPCLinuxV100R005C00SPC030 (kernel/tools/open_source excluded)

source/bootloader/u-boot-2020.01/arch/arm/cpu/arm926ejs/lpc32xx/timer.c

@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2011 Vladimir Zapolskiy <vz@mleia.com>
+ */
+
+#include <common.h>
+#include <time.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/clk.h>
+#include <asm/arch/timer.h>
+#include <asm/io.h>
+
+static struct timer_regs  *timer0 = (struct timer_regs *)TIMER0_BASE;
+static struct timer_regs  *timer1 = (struct timer_regs *)TIMER1_BASE;
+static struct clk_pm_regs *clk    = (struct clk_pm_regs *)CLK_PM_BASE;
+
+static void lpc32xx_timer_clock(u32 bit, int enable)
+{
+	if (enable)
+		setbits_le32(&clk->timclk_ctrl1, bit);
+	else
+		clrbits_le32(&clk->timclk_ctrl1, bit);
+}
+
+static void lpc32xx_timer_reset(struct timer_regs *timer, u32 freq)
+{
+	writel(TIMER_TCR_COUNTER_RESET,   &timer->tcr);
+	writel(TIMER_TCR_COUNTER_DISABLE, &timer->tcr);
+	writel(0, &timer->tc);
+	writel(0, &timer->pr);
+
+	/* Count mode is every rising PCLK edge */
+	writel(TIMER_CTCR_MODE_TIMER, &timer->ctcr);
+
+	/* Set prescale counter value */
+	writel((get_periph_clk_rate() / freq) - 1, &timer->pr);
+
+	/* Ensure that the counter is not reset when matching TC */
+	writel(0,  &timer->mcr);
+}
+
+static void lpc32xx_timer_count(struct timer_regs *timer, int enable)
+{
+	if (enable)
+		writel(TIMER_TCR_COUNTER_ENABLE,  &timer->tcr);
+	else
+		writel(TIMER_TCR_COUNTER_DISABLE, &timer->tcr);
+}
+
+int timer_init(void)
+{
+	lpc32xx_timer_clock(CLK_TIMCLK_TIMER0, 1);
+	lpc32xx_timer_reset(timer0, CONFIG_SYS_HZ);
+	lpc32xx_timer_count(timer0, 1);
+
+	return 0;
+}
+
+ulong get_timer(ulong base)
+{
+	return readl(&timer0->tc) - base;
+}
+
+void __udelay(unsigned long usec)
+{
+	lpc32xx_timer_clock(CLK_TIMCLK_TIMER1, 1);
+	lpc32xx_timer_reset(timer1, CONFIG_SYS_HZ * 1000);
+	lpc32xx_timer_count(timer1, 1);
+
+	while (readl(&timer1->tc) < usec)
+		/* NOP */;
+
+	lpc32xx_timer_count(timer1, 0);
+	lpc32xx_timer_clock(CLK_TIMCLK_TIMER1, 0);
+}
+
+unsigned long long get_ticks(void)
+{
+	return get_timer(0);
+}
+
+ulong get_tbclk(void)
+{
+	return CONFIG_SYS_HZ;
+}